Allocated but unannounced space
Every block here was allocated or assigned by a regional internet registry, and none of them appeared in any routing table we collected at our last snapshot — neither as a route of their own, nor covered by a larger announcement, nor carved up into more specifics.
“Unannounced” does not mean “unused”
Plenty of allocated space is deliberately kept off the public internet: private interconnects, lab and lawful-intercept ranges, networks reachable only inside one operator, and space held in reserve. Some of it is announced somewhere our collectors cannot see, which is a limit of our vantage points rather than a fact about the block.
It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today. Nothing on this page means a block is unallocated, available, or free to announce.
Browse by registry
Browse by country
Countries with the most unannounced blocks, largest first.
Unannounced blocks in Japan
1,446 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 101.203.192.0/18 | 16.4k | APNIC |  JP | 8th Mar 2011 |
| 101.203.48.0/20 | 4.1k | APNIC | JP | 7th Mar 2011 |
| 101.203.80.0/22 | 1k | APNIC | JP | 7th Mar 2011 |
| 101.203.86.0/23 | 512 | APNIC | JP | 7th Mar 2011 |
| 101.203.96.0/19 | 8.2k | APNIC | JP | 7th Mar 2011 |
| 101.97.128.0/17 | 32.8k | APNIC | JP | 7th Apr 2011 |
| 103.1.140.0/22 | 1k | APNIC | JP | 18th Apr 2011 |
| 103.10.112.0/22 | 1k | APNIC | JP | 14th Jun 2011 |
| 103.10.244.0/22 | 1k | APNIC | JP | 4th Aug 2011 |
| 103.101.72.0/22 | 1k | APNIC | JP | 20th Sept 2017 |
| 103.106.48.0/22 | 1k | APNIC | JP | 18th Dec 2017 |
| 103.115.3.0/24 | 256 | APNIC | JP | 22nd Jun 2023 |
| 103.12.16.0/22 | 1k | APNIC | JP | 29th May 2012 |
| 103.13.20.0/22 | 1k | APNIC | JP | 30th May 2012 |
| 103.13.24.0/23 | 512 | APNIC | JP | 30th May 2012 |
| 103.13.26.0/24 | 256 | APNIC | JP | 30th May 2012 |
| 103.131.132.0/23 | 512 | APNIC | JP | 19th Sept 2023 |
| 103.136.152.0/22 | 1k | APNIC | JP | 11th Mar 2019 |
| 103.139.250.0/23 | 512 | APNIC | JP | 11th Jun 2019 |
| 103.14.176.0/22 | 1k | APNIC | JP | 6th Aug 2012 |
| 103.140.200.0/23 | 512 | APNIC | JP | 4th Jul 2019 |
| 103.140.48.0/23 | 512 | APNIC | JP | 19th Jun 2019 |
| 103.142.127.0/24 | 256 | APNIC | JP | 27th Aug 2019 |
| 103.146.114.0/23 | 512 | APNIC | JP | 12th Dec 2019 |
| 103.148.30.0/23 | 512 | APNIC | JP | 30th Jan 2020 |
| 103.15.68.0/22 | 1k | APNIC | JP | 20th Aug 2012 |
| 103.15.76.0/22 | 1k | APNIC | JP | 21st Aug 2012 |
| 103.152.130.0/23 | 512 | APNIC | JP | 23rd Jun 2020 |
| 103.153.26.0/23 | 512 | APNIC | JP | 9th Jul 2020 |
| 103.154.42.0/24 | 256 | APNIC | JP | 5th Aug 2020 |
| 103.157.142.0/23 | 512 | APNIC | JP | 20th Oct 2020 |
| 103.16.8.0/22 | 1k | APNIC | JP | 30th Jan 2013 |
| 103.161.88.0/23 | 512 | APNIC | JP | 6th Jan 2021 |
| 103.164.96.0/24 | 256 | APNIC | JP | 17th Mar 2021 |
| 103.165.188.0/23 | 512 | APNIC | JP | 8th Apr 2021 |
| 103.166.237.0/24 | 256 | APNIC | JP | 7th May 2021 |
| 103.167.42.0/23 | 512 | APNIC | JP | 13th May 2021 |
| 103.17.188.0/22 | 1k | APNIC | JP | 5th Mar 2013 |
| 103.172.162.0/23 | 512 | APNIC | JP | 1st Sept 2021 |
| 103.173.180.0/23 | 512 | APNIC | JP | 25th Sept 2021 |
| 103.173.212.0/23 | 512 | APNIC | JP | 27th Sept 2021 |
| 103.173.8.0/24 | 256 | APNIC | JP | 8th Sept 2021 |
| 103.177.65.0/24 | 256 | APNIC | JP | 29th Nov 2021 |
| 103.179.158.0/23 | 512 | APNIC | JP | 17th Jan 2022 |
| 103.183.76.0/23 | 512 | APNIC | JP | 8th Mar 2022 |
| 103.19.240.0/22 | 1k | APNIC | JP | 8th Apr 2013 |
| 103.192.120.0/22 | 1k | APNIC | JP | 18th Jul 2015 |
| 103.192.228.0/22 | 1k | APNIC | JP | 23rd Jul 2015 |
| 103.199.220.0/22 | 1k | APNIC | JP | 11th Nov 2015 |
| 103.2.12.0/22 | 1k | APNIC | JP | 20th Apr 2011 |